1. Field of the Invention
The present invention relates to a method of manufacturing molding members composed of a thermoplastic synthetic resin material.
2. Description of the Related Art
In order to manufacture molding members, typically for automobiles, it is generally known to mold the resin material, either by an injection process or by an extrusion process, into an elongate shaped body with a cross-section corresponding to that of the molding member, and to cut the shaped body on at least one end into a predetermined length of the molding member. However, the resultant cut surface is left on the molding member as being clearly visible and accessible from outside when the molding member is mounted in place. Such a cut surface not only degrades the appearance but also acts as a possibly harmful edge. It has thus been a conventional practice to carry out an appropriate terminal end treatment, e.g. by covering the cut surface with an end cap, which necessitates troublesome and time consuming production steps, and which is thus quite disadvantageous.
To eliminate the above-mentioned terminal end treatment thereby to improve the productivity, there has been a proposal wherein an elongate shaped body formed of a synthetic resin material is cooled down at first, and is then subjected to cutting by means of a cutting blade to which a high frequency voltage is applied (cf. Japanese Patent Application Laid-open Publication Nos. 54-11,977 and 61-108,027). With such a cutting process, however, the resin material in contact with, or in the vicinity of, the cutting blade is subjected to a melt-down to form a cut surface which is significantly distinct in the appearance from the remaining outer surface of the molding member. Moreover, as the blade is brought into contact with the molten resin material during the cutting, it is quite difficult to form a smooth and even cut surface and to achieve a refined appearance.